1. Reproductive Physiology of Beef and Cattle
Suporn Katawatin
Department of Animal Science
Khon Kaen University

2. Reproduction is one of the most important consideration determining the profit of cattle production

4. (85 days) HERD HEALTH ARTIFICIAL INSEMINATION DAYS OPEN
RECORD
NUTRITION
ESTROUS DETECTION
MANAGEMENT
HERD HEALTH
DAYS OPEN
(85 days)
FEMALE FERTILITY
REDUCE AGE AT 1ST CALVING
INCREASE % COWS CYCLING
TREAT PROBLEM COWS
CONTROL GENITAL DISEASE
PREGNANCY DIAGNOSIS
ARTIFICIAL INSEMINATION
IMPROVE AI TECHNIQUE
USE GOOD QUALITY SEMEN
BREED COWS IN STANDING HEAT

5. to show regular cyclic breeding activity
Good reproduction is …
to show regular cyclic breeding activity

6. Reproductive Physiology
Male and Female Reproductive Anatomy
Puberty : age or body weight
Sexual maturity
Estrous Cycle
Mating or Breeding
Calving
Lactation
Recycling

7. Female Reproductive Characteristics of Cattle and Buffalo
Parameters
Cattle
Buffalo
Age at puberty (mth)
15 (10-24)
21 (15-36)
Estrous cycle
Length (d)
Estrus (h)
21 (14-29)
18 (12-30)
21 (18-22)
21 (17-24)
Ovulation
Type
Time from onset (h)
Spontaneous
30 (18-48)
32 (18-45)

8. Female Reproductive Characteristics of Cattle and Buffalo
Parameter
Cattle
Buffalo
Life span of CL (d) 16
Fertilizable life of ova (h)
(20 – 24) ??
Entry of ova into uterus
(h after ovulation)
90 (64-96)
Gestation length (d)
280 ( )
315 ( )

9. Female Reproductive Characteristics of Cattle and Buffalo
Parameter
Cattle
Buffalo
Age at 1st calving (months)
30 (24-36)
42 (36-56)
Postpartum interval (days)
Uterine involution
First ovulation
45 (32-50)
30 (10-110)
35 (16-60)
75 (35-180)
Calving interval (months)
13 (12-14)
18 (15-21)

10. Areas of controlled reproduction in female cattle
Control estrus
Suppression of estrus
Breeding cattle at younger ages
Controlled reproduction in cattle
Pregnancy testing
Induction of twin births
Control calving
Embryo transfer & in vitro fertilization
Control postpartum interval

11. Heat Detection or Estrous Detection
Estrous behavior

12. Before heat (6-10 h) Smells other cows Attempts to ride other cows
Vulva moist, red slightly swollen

13. Standing heat (18 h) Stand to be ridden Bawls frequently
Nervous & excitable
Off feed and milk
Vulva moist and red
Clear mucous discharge
Eye pupil dilated

14. Clear mucous discharge from vulva
After heat (10 h)
Will not stand
Clear mucous discharge from vulva

15. Hours from the start of estrus
Egg released
Life of egg (6-10 h)
Standing heat (18 h)
After heat (10 h)
Before heat (6-10 h)
Estrus in cow and associated featured

16. Approaches to estrus detection in the cow
Tail-painting & use of chalk
Heat-mount detectors
Use of closed circuit television
Techniques used in estrous detection
Chin-ball devices
Cow activity changes
Use of teaser animals
Progesterone tests
Vaginal probes

18. Hormonal Pattern During
Estrous Cycle in Cow

19. Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Method
Biologic Activity
Gonadotropins
eCG or PMSG
Single injection
Mimics FSH and stimulates follicular growth; long half-life
FSH
Single/multiple injections
Stimulates follicular growth; short half-life
hCG
Mimics LH and induce ovulation

20. Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Method
Biologic Activity
Gonadotropin Releasing Hormone Agonist
GnRH-buselerin
Single injection
Induces release of LH and FSH from the anterior pituitary gland; recruitment and selection of new dominant follicle

21. Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Method
Biologic Activity
Progestogens
Progesterone
Multiple injections
Inhibits ovulation by suppressing LH; mimics action of CL
Synthetic
progestogens
Oral, subcutaneous implant, intravaginal device

22. Method of Administration
Hormones Used for Induction of Estrus and Ovulation
Type of hormones
Method of Administration
Biologic Activity
Estrogens
Estradiol
conjugates
Injection, implant
Induce premature regression of CL, and enhances response to progestrogens
Prostaglandins
PGF2 or
synthetic
analogs
Single intramuscular injection
Induces regression of CL during responsive phases

23. End of Treatment to Estrus
Protocols for Inducing Estrus and Ovulation in
Acyclic Cattle and Buffalo
Treatment
End of Treatment to Estrus
Prepubertal or
postpartum
suckled cows
Estrogen on day 1 followed by days of progesterogen, eCG given on last day (optional)
Within 5 days
Postpartum milked
cows
GnRH on day 14 postpartum
GnRH (day 0) and PGF (day 6)
1 day
2-4 days

24. End of treatment to estrus
Techniques for Synchronizing Estrus
in Cyclic Cattle
Method
Treatment Regimen
End of treatment to estrus
PGF
Two injections
(11-12 days apart)
3-5 days: AIDE/TAI
GnRH + PGF
Inject GnRH (day 0), PGF (day 6)
2-4 days: TAI
GnRH + PGF + GnRH
Inject GnRH (day 0), PGF (day 7), GnRH (day 8 or 9)

25. End of treatment to estrus
Techniques for Synchronizing Estrus in Cyclic Cattle.
Method
Treatment Regimen
End of treatment to estrus
Progestogen + estrogen
Estrogen injection (day 1), CIDR (day 1-9X
3-5 days : AIDE/TAI
Progestogen +PGF
Progestogen (days1-7), PGF (day 6)
2-3 days: AIDE/TAI

26. Ovulate follicle Start new follicle wave
OVSync
Breed (cows)
GnRH (100ug)
PGF2 (35mg)
GnRH (100ug)
7 days
48 h
24 h
Ovulate follicle Start new follicle wave
Ovulate follicle
Regress corpora lutea
Timing and purpose of hormones to synchronize ovulation in lactating dairy cow (Pursley et al., 1995)

27. Days calving to conception Calving interval (days)
Measure Reproductive Efficiency
Trait
Definition
First calving
Age (months)
Days open
Days calving to conception
Calving interval (days)
Days between successive calving
Total cows
First service conception rate (%)
No. pregnant 1st service X 100
No. bred 1st service

28. No. of services in all cows
Measure Reproductive Efficiency
Trait
Definition
Services per conception
No. of services in all cows
Total conceptions
Pregnancy rate (%)
No. of cows pregnant X 100
Total cows in herd
Calving rate (%)
No. of calves born X 100
Net calf crop (%)
Total calves weaned X 100

29. Book Suggestion Hafez, E.S.E. and B. Hafez. 2000. Reproduction in
Farm Animals. 7th ed. Lippincott Williams &
Wilkins, New York.
Gordon, I Controlled Reproduction
in Cattle & Buffaloes. CAB International.
Bearden, H.J. and J.W. Fuquay Applied Animal
Reproduction 4th ed. Prentice Hall.

31. Approximate Values for Selected Reproductive Events in Female Domesticated Mammals
 Species
 Length of cycle (days)
 Duration of estrus (hours)
 Approximate time of ovulation
 Normal breeding season
 Cow
Mean=20.5  Range
Mean < 10  Range
 30 h after beginning of estrus 
 All year
 Buffalo
Mean=21  Range
Mean < 15  Range
 32 h after beginning of estrus
 All year 
 Mare
Mean=21  Range
Mean=120  Range
 Near end of estrus
 Spring & summer
 Ewe
Mean=16  Range
Mean=30  Range
 26 h after beginning of estrus 
 Fall (variable with breed)
 Doe
Mean=20  Range
Mean=40  Range
 On 2nd day of estrus
 Fall
 Sow
Mean=48  Range
 36 h after beginning of estrus